Guide to Hardwood Floor Finishes

How to choose what’s right for you.

We’re not going out on a limb when we say hardwood floors are one of the most popular, value-adding features in your home. Homebuyers love ‘em.

But hardwood floors need regular maintenance and refinishing to keep them looking spiffy.

How much wear and tear your floors get determines how often you need to refinish them and what product you use. A household with just two adults might only have to refinish every 10 years; a home with adults, kids, and a dog might need to refinish every three to four years.

Wax is the time-tested, old-fashioned way to refinish wood floors and was routinely used before polyurethanes became available in the 1970s. Both paste and liquid versions are making a comeback with homeowners who want a mellow, low-sheen look, and with those who prefer to use natural products with low VOCs and toxicity.

It’s applied by hand working small areas at a time, which makes it DIY-friendly (but labor-intensive). It’s also easy to touch up a wax finish, so ongoing maintenance is simple.

If you don’t want to darken your wood (which wax tends to do), first apply a base coat of shellac or sanding sealer that penetrates and seals the wood. Two to three coats of wax are recommended.

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Water-Based Polyurethane

Pros

Cons

Fast drying time (2 to 4 hours between coats)

More expensive than oil poly

Low odor; low VOCs

Less tough than oil poly

Doesn’t yellow like oil polys

Easy to apply; good for DIYers

Polyurethanes are today’s standard floor finish. Water-based varieties used to have a reputation for being eco-friendly (still true) but not as durable as regular polys. However, today’s water-based polys are nearly as tough as their oil-based cousins.

One difference is final color: Water-based polys dry clear; oil-based polys have a slight amber tint.

Water-based polyurethane has very low VOC content and is easy for a DIYer to apply. Three to four coats are recommended. You can use a water-based polyurethane over an oil-based poly as long as the old finish has completely cured (two to three weeks).

Especially good for: eco-conscious DIYers

Cost: $40 to $60 per gallon covers 400 to 500 square feet

Oil-Based Polyurethane

Pros

Cons

Less expensive than water-based poly

Long drying time (8 to 10 hours between coats)

Extremely tough

High odor during application; high VOCs

Easy to apply

Gets yellow with age (benefit to some)

Oil-based polys are the mainstay of floor finishing and widely used by professional finishers.

Although they’re tough, long-lasting, and less-expensive than water-based polys, oil-based polys have a higher VOC content and stronger odor during application. A coat takes 8 to 10 hours to dry, so you’ll want to vacate your house until the floor is completely dry — and bring your pets with you. Two to three coats are recommended.

Professional floor refinishers report some problems when using an oil-based poly over a water-based poly. Best advice: Don’t do it.

Especially good for: professionally finished floors at a reasonable price

Cost: $30 to $40 per gallon covers 500 to 600 square feet; it’s $1 to $2 per square foot to have a pro do it.

Acid-Cured (Swedish) Finish

Pros

Cons

Extremely hard and durable

Difficult to refinish (must use acid-cured finish if used previously)

Fast drying time (2 hours) but up to 60 days to fully cure

Volatile odors; high VOCs

More expensive than most finishes

Pro-only application

The Cadillac (or Volvo) of floor finishes, acid-cured Swedish finishes are for pro application only. They’re among the toughest of all hardwood flooring finishes, and the most expensive. They’re sometimes called conversion varnish sealers.

Acid-cured finishes have extremely high VOC content; you’ll have to bunk elsewhere for a few days after finishing to give the odors a chance to clear. The finish takes up to 60 days to fully cure, but you can walk on it after three days. Keep furniture off for two weeks, and rugs off for the full 60 days so the fibers don’t stick.

Especially good for: high-end homes with flooring made from exotic woods and floors with elaborate inlay designs

Cost: $3.75 to $5 per square foot professionally applied

Moisture-Cured Urethane

Pros

Cons

Extremely durable (one of the hardest)

Extremely high VOCs (fumes may last for weeks)

Expensive

Pro-only application

Fast drying time allows for multiple coats per day

Low humidity extends drying time

This is a durable finish that’s a step up in toughness and longevity from water- and oil-based polyurethane. It’s tricky to apply and isn’t recommended for DIY — it dries very fast, so speed and a deft touch are needed to avoid lap marks.

It has a high VOC content, making a respirator and good ventilation a must during application. Homeowners and pets should vacate the house during application and for up to two weeks afterward.

Especially good for: high-traffic areas and homes with multiple kids and dogs

Cost: $2 to $4 per square foot professionally applied

Penetrating Oil Sealer

Pros

Cons

Easy for DIYers to apply

Not as durable as a poly finish

Non-toxic ingredients

Should be reapplied every 2 to 3 years

Mild odor

Mellow sheen

Oil sealers have been used for centuries to protect and moisture-proof wood. They’re easy to apply, and spot touch-ups are a snap. Because it penetrates the wood, an oil sealer enhances grain patterns and deepens the color of the wood. The finish itself doesn’t scratch, but recoating usually is needed every two to three years as the finish wears down.

The basic ingredient is tung oil, a naturally occurring, low-VOC oil that hardens as it dries. It needs long drying times between coats (24 to 48 hours), so finishing a floor with the recommended three coats can take several days.

Especially good for: historic homes with antique flooring; DIYers

Cost: $60 to $70 per gallon covers 500 square feet

Aluminum Oxide

Pros

Cons

Extermely hard and durable (25 years)

Only available with prefinished flooring

Difficult to refinish

After 25 years, you might have to replace the flooring

This super-tough finish only comes on prefinished wood planks. You won’t apply it yourself, but you’ll need to know it’s there if you ever decide to refinish it. It requires special refinishing techniques, like sanding with milder grits before using heavier grits. Your floor refinisher can determine if your flooring is covered with an aluminum oxide coating.

Shellac

Polyurethane floor products have surpassed the usefulness of this time-honored wood finish. Houses built before 1970 may have hardwood floors finished with shellac, and you can maintain and refinish them with another coating of shellac. It’s not compatible with more modern finishes, such as polyurethane, so only refinish shellac with wax or another coating of shellac.

Test for shellac by dribbling a few drops of water on an inconspicuous spot. If the finish turns milky white, it’s shellac.

Shellac is a natural product that’s non-toxic and produces few VOCs. It’s not as tough and durable as polyurethanes, and is susceptible to stains from water and other spills. However, it’s easy to repair scratched areas by rubbing out the scratches with denatured alcohol, then reapplying shellac.

Shellac pairs well with wax. Use shellac as a base coat, and finish with two or three coats of hand-rubbed wax.

Two Options for Refinishing

Does your floor need a touch-up or an overhaul?

1. Touch-up. For surface scratches and normal wear and tear, lightly sand the finish (called screening) and apply a new topcoat. You’ll want to use the same type of finish product that was on your flooring originally.

2. Overhaul. For more damaged flooring, you’ll want to completely sand the old finish off down to the bare wood. Once you’ve done that, you can apply any finish.

has written seven books on home improvement and hundreds of articles on home-related topics. He’s been a residential builder, the editorial director of the Black & Decker Home Improvement Library, and the executive editor of Better Homes and Gardens magazine. Follow John on Google+.